CVD system in a 3"-i.d. tube furnace (1200°C) with pressures down to ~ 1 Torr and fast-acting electro-pneumatic valves for switching source gases; integrated time-resolved reflectivity diagnostics and remote video imaging of growth dynamics. The system is in proximity of tunable ns-lasers for laser diagnostics of CVD processes, or for combined laser-CVD (e.g. for doping of nanotubes during CVD growth, or laser-generation of catalyst nanoparticles for CVD, etc.).

Thermal CVD of single and multiwall carbon nanotubes, nanotube arrays, and nanotube patterns at atmospheric pressure and flow.

ns-Laser Vaporization Synthesis of SWNTs, NWs, NPsSWNTs and nanowires are produced by pulsed Nd:YAG laser-irradiation (30 Hz, Q-switched or free-running) of composite pellets in a 2" tube furnace with variable pressure control. Excimer laser ablation of materials into variable pressure background gases is used for nanoparticle generation in proximity of ns-laser diagnostics.

fs-laser synthesis of metal or alloy nanoparticles by through-thin-film ablation – nm’s thin metal films deposited on transparent substrates are ablated by single fs-laser pulses. Gated ICCD imaging or Rayleigh scattering diagnostics are used to observe the nanoparticle cloud in vacuum or background gases. Samples are collected on TEM grids for analysis.

Wet/Dry Processing and Assembly of Organic, Inorganic, and Hybrid Materials and Devices

Photolithographic-, E-beam-, FIB-Patterning/Wiring of Nanomaterials for Devices
(Through the Nanofabrication Research Laboratory) Processing of nanomaterials including spin-coating, dielectrophoretic deposition, etc. combined with photo- and e-beam lithographic techniques and FIB electrode placement for the addressing of nanomaterials as prototype devices.

Controlled atmosphere dual glove box evaporator system for inorganic films and organic electronicsAn MBraun Labmaster double glove box system with integrated vacuum deposition chamber (Angstrom Amod e-beam and thermal evaporator) and spin coater (Specialty Coating Systems Model SCS G3) is available for physical vapor deposition of metals and small-molecule organics and for spin coating of polymers in a clean, inert environment. Thermal chambers have six sources, including two RADAK sources for small-molecule deposition with co-deposition capability, which enable multilayer deposition, gradient and doping film deposition at controlled substrate temperatures (RT to 400°C). The system is also equipped for computer-controlled e-beam deposition with four pocket electron-beam sources and two thermal sources for high melting point metals and inorganic compound thin film deposition. A 400°C vacuum oven is mounted to one end of the glove box. The system has various shadow masks for patterning electrodes for various organic electronic devices including OFETs, OLEDs, OPVs, and spin valves. The system enables the assembly of organic and inorganic multilayer thin films with Ångstrom thickness resolution for organic electronic devices.

Sonospray deposition of nanomaterials and organics
Computer-controlled sono-spray deposition of nano materials, polymers, and nano composites from solutions and suspensions for uniform or patterned deposition on small or large areas (up to 1ft x 1ft) with minimum feature size of 1.5 mm. The system enables multilayer deposition on various substrates, including polymers, while controlling the substrate temperature (up to 180C). A micro-syringe pump feeds a solution allowing deposition from small (<10ml) volumes of solution and a dual-syringe configuration allows simultaneous deposition from two different solutions with variable ratio. The system is also equipped with a sono-syringe, to prevent precipitation of material during deposition (min required volume 20ml).

2D Crystal Stamping
A microscope based setup to transfer exfoliated or CVD-grown layers of 2D materials from polymer-coated ribbons is available, allowing the stamp-fabrication of 2D heterostructures.

Optical Characterization and Laser Spectroscopy of Nanomaterials

Ultrafast femtosecond laser pump-probe spectroscopy of nanomaterials and composites
A Coherent Legend Titanium sapphire based amplifier, providing pulses centered at 800 nm with ~2 mJ/pulse, 45 fs short durations, and operating at 1 kHz repetition rate, is used to pump an optical parametric amplifier (OPA), and a small portion is used to generate spectrally broad white light continuum (450-950 nm). The tunable output of the OPA (400-2500nm) is used as pump, and the white light continuum is used as probe. This pump probe setup is capable of studying samples in liquid and solid phases. The spatial resolution in transmission mode, is ~ micron, and in reflection mode is ~10 microns. In both modes the temporal resolution is ~ 45 fs providing with sub-milli-OD absorbance sensitivity at 500Hz acquisition rate.

Tunable (0.25 – 1.6 µm) fs/ps laser system (nJ @ 80 MHz)
Ti:Sapphire-based oscillator coupled to second- and third-harmonic generator crystals, along with OPO, may be run in either fs or ps mode. Coupled to confocal microscope with XYZ control for Raman spectroscopy or fluorescence measurements Provides nj/ps-pulse at 80MHz to avoid damage to nanostructures.